const express = require("express");
const router = express.Router();
const { pool } = require("../config/database");
const logger = require("../config/logger");

// Middleware to check customer auth from session
const requireCustomerAuth = (req, res, next) => {
  if (!req.session || !req.session.customerId) {
    return res
      .status(401)
      .json({ success: false, message: "Please login to continue" });
  }
  next();
};

// ===========================
// CART ROUTES
// ===========================

// Get cart items
router.get("/cart", requireCustomerAuth, async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT cc.id, cc.product_id, cc.quantity, cc.variant_color, cc.variant_size, cc.added_at,
              p.name, p.price, p.imageurl, p.slug
       FROM customer_cart cc
       JOIN products p ON p.id = cc.product_id
       WHERE cc.customer_id = $1
       ORDER BY cc.added_at DESC`,
      [req.session.customerId]
    );

    const items = result.rows.map((row) => ({
      id: row.id,
      productId: row.product_id,
      name: row.name,
      price: parseFloat(row.price),
      image: row.imageurl,
      slug: row.slug,
      quantity: row.quantity,
      variantColor: row.variant_color,
      variantSize: row.variant_size,
      addedAt: row.added_at,
    }));

    const total = items.reduce(
      (sum, item) => sum + item.price * item.quantity,
      0
    );

    res.json({
      success: true,
      items,
      itemCount: items.length,
      total: total.toFixed(2),
    });
  } catch (error) {
    logger.error("Get cart error:", error);
    res.status(500).json({ success: false, message: "Failed to get cart" });
  }
});

// Add to cart
router.post("/cart", requireCustomerAuth, async (req, res) => {
  try {
    const { productId, quantity = 1, variantColor, variantSize } = req.body;

    if (!productId) {
      return res
        .status(400)
        .json({ success: false, message: "Product ID is required" });
    }

    // Check if product exists
    const productCheck = await pool.query(
      "SELECT id, name FROM products WHERE id = $1",
      [productId]
    );
    if (productCheck.rows.length === 0) {
      return res
        .status(404)
        .json({ success: false, message: "Product not found" });
    }

    // Insert or update cart item
    const result = await pool.query(
      `INSERT INTO customer_cart (customer_id, product_id, quantity, variant_color, variant_size)
       VALUES ($1, $2, $3, $4, $5)
       ON CONFLICT (customer_id, product_id, variant_color, variant_size)
       DO UPDATE SET quantity = customer_cart.quantity + EXCLUDED.quantity, updated_at = CURRENT_TIMESTAMP
       RETURNING id`,
      [
        req.session.customerId,
        productId,
        quantity,
        variantColor || null,
        variantSize || null,
      ]
    );

    logger.info(
      `Cart item added for customer ${req.session.customerId}: ${productId}`
    );

    res.json({
      success: true,
      message: "Added to cart",
      cartItemId: result.rows[0].id,
    });
  } catch (error) {
    logger.error("Add to cart error:", error);
    res.status(500).json({ success: false, message: "Failed to add to cart" });
  }
});

// Update cart quantity
router.put("/cart/:id", requireCustomerAuth, async (req, res) => {
  try {
    const { quantity } = req.body;

    if (!quantity || quantity < 1) {
      return res
        .status(400)
        .json({ success: false, message: "Quantity must be at least 1" });
    }

    const result = await pool.query(
      `UPDATE customer_cart SET quantity = $1, updated_at = CURRENT_TIMESTAMP
       WHERE id = $2 AND customer_id = $3
       RETURNING id`,
      [quantity, req.params.id, req.session.customerId]
    );

    if (result.rows.length === 0) {
      return res
        .status(404)
        .json({ success: false, message: "Cart item not found" });
    }

    res.json({ success: true, message: "Cart updated" });
  } catch (error) {
    logger.error("Update cart error:", error);
    res.status(500).json({ success: false, message: "Failed to update cart" });
  }
});

// Remove from cart
router.delete("/cart/:id", requireCustomerAuth, async (req, res) => {
  try {
    const result = await pool.query(
      "DELETE FROM customer_cart WHERE id = $1 AND customer_id = $2 RETURNING id",
      [req.params.id, req.session.customerId]
    );

    if (result.rows.length === 0) {
      return res
        .status(404)
        .json({ success: false, message: "Cart item not found" });
    }

    res.json({ success: true, message: "Removed from cart" });
  } catch (error) {
    logger.error("Remove from cart error:", error);
    res
      .status(500)
      .json({ success: false, message: "Failed to remove from cart" });
  }
});

// Clear cart
router.delete("/cart", requireCustomerAuth, async (req, res) => {
  try {
    await pool.query("DELETE FROM customer_cart WHERE customer_id = $1", [
      req.session.customerId,
    ]);
    res.json({ success: true, message: "Cart cleared" });
  } catch (error) {
    logger.error("Clear cart error:", error);
    res.status(500).json({ success: false, message: "Failed to clear cart" });
  }
});

// ===========================
// WISHLIST ROUTES
// ===========================

// Get wishlist items
router.get("/wishlist", requireCustomerAuth, async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT cw.id, cw.product_id, cw.added_at,
              p.name, p.price, p.imageurl, p.slug
       FROM customer_wishlist cw
       JOIN products p ON p.id = cw.product_id
       WHERE cw.customer_id = $1
       ORDER BY cw.added_at DESC`,
      [req.session.customerId]
    );

    const items = result.rows.map((row) => ({
      id: row.id,
      productId: row.product_id,
      name: row.name,
      price: parseFloat(row.price),
      image: row.imageurl,
      slug: row.slug,
      addedAt: row.added_at,
    }));

    res.json({
      success: true,
      items,
      itemCount: items.length,
    });
  } catch (error) {
    logger.error("Get wishlist error:", error);
    res.status(500).json({ success: false, message: "Failed to get wishlist" });
  }
});

// Add to wishlist
router.post("/wishlist", requireCustomerAuth, async (req, res) => {
  try {
    const { productId } = req.body;

    if (!productId) {
      return res
        .status(400)
        .json({ success: false, message: "Product ID is required" });
    }

    // Check if product exists
    const productCheck = await pool.query(
      "SELECT id, name FROM products WHERE id = $1",
      [productId]
    );
    if (productCheck.rows.length === 0) {
      return res
        .status(404)
        .json({ success: false, message: "Product not found" });
    }

    // Insert wishlist item (ignore if already exists)
    await pool.query(
      `INSERT INTO customer_wishlist (customer_id, product_id)
       VALUES ($1, $2)
       ON CONFLICT (customer_id, product_id) DO NOTHING`,
      [req.session.customerId, productId]
    );

    logger.info(
      `Wishlist item added for customer ${req.session.customerId}: ${productId}`
    );

    res.json({ success: true, message: "Added to wishlist" });
  } catch (error) {
    logger.error("Add to wishlist error:", error);
    res
      .status(500)
      .json({ success: false, message: "Failed to add to wishlist" });
  }
});

// Remove from wishlist
router.delete("/wishlist/:id", requireCustomerAuth, async (req, res) => {
  try {
    const result = await pool.query(
      "DELETE FROM customer_wishlist WHERE id = $1 AND customer_id = $2 RETURNING id",
      [req.params.id, req.session.customerId]
    );

    if (result.rows.length === 0) {
      return res
        .status(404)
        .json({ success: false, message: "Wishlist item not found" });
    }

    res.json({ success: true, message: "Removed from wishlist" });
  } catch (error) {
    logger.error("Remove from wishlist error:", error);
    res
      .status(500)
      .json({ success: false, message: "Failed to remove from wishlist" });
  }
});

// Remove from wishlist by product ID
router.delete(
  "/wishlist/product/:productId",
  requireCustomerAuth,
  async (req, res) => {
    try {
      await pool.query(
        "DELETE FROM customer_wishlist WHERE product_id = $1 AND customer_id = $2",
        [req.params.productId, req.session.customerId]
      );

      res.json({ success: true, message: "Removed from wishlist" });
    } catch (error) {
      logger.error("Remove from wishlist error:", error);
      res
        .status(500)
        .json({ success: false, message: "Failed to remove from wishlist" });
    }
  }
);

// Check if product is in wishlist
router.get(
  "/wishlist/check/:productId",
  requireCustomerAuth,
  async (req, res) => {
    try {
      const result = await pool.query(
        "SELECT id FROM customer_wishlist WHERE product_id = $1 AND customer_id = $2",
        [req.params.productId, req.session.customerId]
      );

      res.json({
        success: true,
        inWishlist: result.rows.length > 0,
        wishlistItemId: result.rows[0]?.id || null,
      });
    } catch (error) {
      logger.error("Check wishlist error:", error);
      res
        .status(500)
        .json({ success: false, message: "Failed to check wishlist" });
    }
  }
);

// Get cart count (for navbar badge)
router.get("/cart/count", async (req, res) => {
  try {
    if (!req.session || !req.session.customerId) {
      return res.json({ success: true, count: 0 });
    }

    const result = await pool.query(
      "SELECT COALESCE(SUM(quantity), 0) as count FROM customer_cart WHERE customer_id = $1",
      [req.session.customerId]
    );

    res.json({
      success: true,
      count: parseInt(result.rows[0].count),
    });
  } catch (error) {
    logger.error("Get cart count error:", error);
    res.json({ success: true, count: 0 });
  }
});

// Get wishlist count (for navbar badge)
router.get("/wishlist/count", async (req, res) => {
  try {
    if (!req.session || !req.session.customerId) {
      return res.json({ success: true, count: 0 });
    }

    const result = await pool.query(
      "SELECT COUNT(*) as count FROM customer_wishlist WHERE customer_id = $1",
      [req.session.customerId]
    );

    res.json({
      success: true,
      count: parseInt(result.rows[0].count),
    });
  } catch (error) {
    logger.error("Get wishlist count error:", error);
    res.json({ success: true, count: 0 });
  }
});

module.exports = router;